This invention relates to apparatus for and a method of in situ application of lubricating oil in a lubrication wick installed within its wick support structure. More particularly, this invention is related to the in situ application of a known or desired quantity of lubricating oil into the wicks comprising a wick lubrication system in a fractional horsepower electric motor or the like which supplies lubricant to the bearings of the motor.
Many fractional horsepower motor utilize felt wicks or the like to supply lubricating oil to the rotor bearings of the motor. These bearings may be journal bearings (either sleeve or spherical bearings), or, in some instances, roller element bearings. Typically, the lubricating wick surrounds the rotor shaft of the motor and a portion of the wick is in contact with the shaft so as to continuously supply lubricating oil to the shaft which in turn is then carried into the bearing. In certain motor designs, the lubricating system includes a reservoir wick which contains a supply of lubricant and a lubricant applying wick which is in contact with the reservoir wick and with the shaft or bearing for transferring lubricant from the reservoir wick to the bearing. Also, many electric motors are provided with tubes, slingers, oil catching and retaining shields, and other wicks which collect excess lubricating oil ejected from the bearings and return it to the reservoir wick.
The various wicks in an electric motor are typically carried in the end shields or in other stationary portions of the motor which surround and support the bearing to be lubricated. As is now conventional, the wicks are impregnated (i.e., saturated) with lubricating oil prior to their installation in their respective supporting structures. In practice, it has been found that after the wicks have been installed, there may be significant variations between identical motors as to the quantity of lubricant actually contained in their respective lubricating wicks. This in turn has a direct effect on the minimum operational time of the motor until the wicks need to be reoiled or in some instances on the service life of the motor. Thus, it is highly desirable that the wicks of the motor reliably have a known quantity of oil therein after they have been installed so that the service lives for the motors will be more uniform.
Among many possible reasons for the variation of the amount of lubricant actually contained in the wicks after installation in the motor, it will be appreciated that at some time prior to their installation in a motor, the wicks must be removed from the lubricant in which they were soaked or immersed for filling them with lubricant. Of course, some of the lubricant will drain from the wicks while they are awaiting installation in the motor. Also, if a wick is immediately installed, it will, in all likelihood, have a maximum amount of lubricant therein. However, under actual production or manufacturing conditions, considerable variations may be present between the time the wicks of different motors are installed. Also, certain of the wicks must, out of necessity, be at least partially deformed so as to enable them to be installed in their respective supporting structures. This deformation of the wick has the effect of wringing oil from the wick. Still further, the installation of pre-impregnated wicks is a messy operation. In certain instances, it is highly desirable to keep certain areas of the motor or motor housing free from oil (e.g., surfaces which are intended to be subsequently adhesive bonded together) thus necessitating extra precautions or steps during the manufacture of the motor. This in turn adds to the cost of the motor.
Among the several objects and features of the present invention may be noted the provision of apparatus for and the method of the in situ application of a metered or controlled quantity of lubricating oil in a lubricating wick after it has been installed in its supporting structure;
The provision of such apparatus and method for insuring that each and every wick has the prescribed quantity of lubricant installed therein;
The provision of such apparatus and method in which the lubricant is contained within the structure supporting the wick during the filling of the wick thus providing a cleaner assembly environment;
The provision of such apparatus and method which does not adversely disturb the wick from its position as it is installed in its wick support structure;
The provision of such method and apparatus which may be utilized with automated production equipment to fill the wicks of electric motors or the like with lubricant at normal production speeds;
The provision of such apparatus and method which injects or applies a maximum amount of lubricant into the wick in a mimimum amount of time substantially without spillage or waste of the lubricant;
The provision of such apparatus which is of simple and rugged construction and which is reliable in operation; and
The provision of such apparatus and method which may be readily adapted to apply lubricant to a variety of wick configurations installed in various electric motor designs.
Other objects and features of this invention will be in part apparent and in part pointed out hereinafter.